This invention relates to heat exchange constructional elements, and more particularly, to such elements used as solar collecting roof covers.
Solar collectors are widely used as constructional elements. One example is of the type disclosed in German Offenlegungsschrift No. 2,832,304. According to this example, an extrudable, multi-tier element with hollow chambers is provided with a cover that is transparent to light. The open ends of at least one tier of hollow chambers are connected to a collecting channel. High energy losses from heat dissipation to the environment are reduced by providing for circulation of a liquid medium in only the hollow chambers of a lower tier. At the same time the hollow chambers of the overlying tier contain only air and form an effective insulation. This arrangement has the disadvantage that the liquid medium for the heat exchange is heated at a relatively low rate. In addition, only collector operation is possible.
Accordingly, it is an object of the invention to enhance the utility of solar collectors, particularly those which are used as constructional elements. A related object is to enhance the efficiency of solar collection devices.
Another object of the invention is to increase the rapidity with which heat exchange can take place between the flow medium of a solar collector and the environment. A related object is to enhance the degree of heat utilization in a solar collector.
Still another object of the invention is to provide heat exchange constructional elements with multiple modes of operation, allowing not only collector operation but other modes of operation as well.